Stars and stellar evolution
For the first time, astronomers have used images from the NASA/ESA/CSA James Webb Space Telescope to identify a supernova progenitor that could not be seen by any other telescope: a red supergiant that was located in a nearby galaxy. The supergiant’s surroundings were surprisingly dusty - dusty enough to render it invisible to the NASA/ESA Hubble Space Telescope.
Just a few hundred light-years from Earth, the famous variable star Mira A is huffing and puffing its outer layers to space. Its most recent mass-loss event ejected more material at higher velocity than in past events. A team of astronomers led by Theo Khouri, Chalmers University in Sweden discovered two large clouds of material expanding away from Mira A in observations done by the Very Large Telescope and ALMA telescopes in South America in 2015 and 2023. Those clouds form two lobes of a cosmic "heart" shape surrounding the star. That structure is basically a cloud of dust at the edges, filled by gas from the star.
Astronomers have solved the mystery of a star that dimmed dramatically for nearly 200 days, one of the longest stellar dimming events ever recorded. The culprit appears to be either a brown dwarf or a super Jupiter with an enormous ring system, creating a giant saucer like structure that blocked 97% of the star’s light as it passed in front. This rare alignment offers scientists a unique opportunity to study planetary scale ring systems far beyond our Solar System.
Astronomers have solved a bit of a mystery that had them questioning whether one of the most extreme stars ever observed was about to explode. WOH G64, a massive red supergiant in the Large Magellanic Cloud, began behaving so strangely that researchers suspected it had evolved into a rare yellow hypergiant on the brink of supernova. But new observations from the Southern African Large Telescope reveal the star is still very much a red supergiant, yet still exhibiting strange behaviour.
Using the South Pole Telescope, astronomers have detected powerful stellar flares erupting from stars near the supermassive black hole at the centre of the Milky Way. Operating at millimetre wavelengths that can penetrate the dust obscuring our view of the core of the Galaxy, the telescope caught these dramatic magnetic energy releases in one of the most extreme environments in our Galaxy. The discovery opens a new observational window for studying stellar behaviour in regions previously hidden from view and provides insights into how stars survive and behave in the intense gravitational and radiation environment surrounding the Milky Way's central black hole.
It's been about one millennia since humans directly observed a core-collapse supernova in the Milky Way. That's strange, since there should be 1 or 2 every century. By working with neutrino detectors, the Vera C. Rubin Observatory should be able to detect far more supernovae.
Icy comets contain common crystals that can only be formed in extreme heat. But comets reside in the frigid outer reaches of the Solar System. How did these materials form, and how did they find their way into the Solar System's cold fringes?
We live near a fusion reactor in space that provides all our heat and light. That reactor is also responsible for the creation of various elements heavier than hydrogen, and that's true of all stars. So, how do we know that stars are element generators?
How do blue stragglers defy the aging that turns their mates red? Blue stragglers are found in ancient star clusters, where they outshine stars the same age, looking far bluer and younger than their true age. Astrophysicists have tried to understand blue stragglers for decades. New research using the NASA/ESA Hubble Space Telescope is finally revealing how these ageless stars come to be and why they thrive in quieter cosmic neighbourhoods.
The Helix Nebula is one of the closest and brightest planetary nebula. It's what's left of a dying star and has nothing to do with planets. Our Sun will end up as one of these sumptuous displays, and a new JWST image reveals even more detail in the stunning nebula.
The Hubble Mission Team has released another image of the space telescope's study of star formation. This image shows the dark cloud Lupus 3, a star-forming region about 500 light-years away. Lupus 3 contains bright young T-Tauri stars, and 2 hot young stars that are creating a beautiful nebula.
Newly developing stars shrouded in thick dust get their first baby pictures in these images from NASA’s Hubble Space Telescope. Hubble took these infant star snapshots in an effort to learn how massive stars form. Protostars are shrouded in thick dust that blocks light, but Hubble can detect the near-infrared emission that shines through holes carved in the gas by the young stars themselves.
The Ring Nebula is a well-studied planetary nebula about 2,570 light-years away. Nnew observations of the nebula with a new instrument have revealed a previously unseen component. The William Herschel Telescope used its WEAVE instrument to detect a massive 'iron bar' inside the nebula's inner layer.
Young protostars populate the cloudy regions in the Orion Molecular Cloud complex in these images from the Hubble Space Telescope. Three of the telescope's new images are part of a scientific effort to understand the gaseous, dusty envelopes around protostars. Scientists know that these young stars have powerful stellar winds and jets that carve caverns and bubbles out of the surrounding gas, but they have unanswered questions about that process.
NASA’s Hubble Space Telescope has captured stunning new image of HH 80/81, a pair of objects created when supersonic jets from a newborn star slam into previously expelled gas clouds, heating them to extreme levels. These jets, powered by a protostar 20 times more massive than our Sun, stretch over 32 light years through space and travel at speeds exceeding 1,000 kilometres per second, making them the fastest outflows ever recorded from a young star.
A disparate collection of young stellar objects bejewels a cosmic panorama in the star-forming region NGC 1333 in this new image from NASA’s Hubble Space Telescope. To the left, an actively forming star called a protostar casts its glow on the surrounding gas and dust, creating a reflection nebula. Two dark stripes on opposite sides […]
Betelgeuse is the star that everybody can't wait to see blow up, preferably sooner than later. That's because it's a red supergiant on the verge of becoming a supernova and there hasn't been one explode this close in recorded human history. It's been changing its brightness and showing strange surface behavior, which is why astronomers track its activity closely. Are these changes due to its aging process? Do they mean it's about to blow up? Probably not.
Supernovae play a crucial role in the formation and evolution of new stars. But where they occur is nearly as important as when. A new study looks at where supernovae will occur in the Triangulum Galaxy, which will help astronomers understand the role of supernovae in more detail.
Gas and dust flowing from stars can, under the right conditions, clash with a star's surroundings and create a shock wave. Now, astronomers using the European Southern Observatory's Very Large Telescope (ESO's VLT) have imaged a beautiful shock wave around a dead star—a discovery that has left them puzzled. According to all known mechanisms, the small, dead star RXJ0528+2838 should not have such a structure around it. This discovery, as enigmatic as it's stunning, challenges our understanding of how dead stars interact with their surroundings.
A new survey of K-type stars in the Sun's neighbourhood reveals important information about their ability to sustain their habitable zones. These stars are less massive, cooler, and dimmer than the Sun, but stay on the main sequence for many tens of billions of years. Their long lives can create the stable conditions necessary for life to develop on exoplanets.
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